Writing instrument



Aug. 16, 1966 w. c. GANZ WRITING INSTRUMENT 4 Sheets-Sheet 1 Original Filed Oct. '7, 1963 27 INVENTOR.

WALTER Q GANZ,

ATTORNEY$ Aug. 16, 1966 w. c. GANZ WRITING INSTRUMENT 4 Sheets-$heet 2 Original Filed Oct. 7. 1963 INVENTOR. WALTER c. GANZ %d% ATTORNEYS Aug. 16, 1966 w. c. GANZ WRITING INSTRUMENT 4 Sheets-Sheet 3 Original Filed 001:. 7, 1963 INVENTOR. WALTER C. GANZ BY Q Q 3 ATTORNEYS Aug. 16, E966 w. c. GANZ WRITING INSTRUMENT 4 Sheets-Sheet 4 Original Filed Oct. '7, 1963 INVENTOR. WALTER C. GANZ BY 2 g ATTORNEYS United States Patent 3,266,465 WRITING INSTRUMENT Walter C. Ganz, Jackson Heights, N.Y., assignor to Chromatic Corporation, Brooklyn, N.Y., a corporation of New York Continuation of abandoned application Ser. No. 314,109, Oct. 7, 1963. This application Sept. 11, 1964, Ser. No. 395,786

12 Claims. (Cl. 120-4213) This application is a continuation of application Ser. No. 314,109, now abandoned.

The present invention relates to an improved writing instrument having multiple writing units and more particularly to a writing instrument having multiple selectable writ-ing units mounted, so that a desired unit may be selectably positioned into operative or writing use.

.Prior art multiple unit writing instruments utilized complex mounting and selector mechanism, which often maltfunctioned in use and were difiicult to repair. Some prior art writing instruments slidably mounted its writing units in a housing which units were moved into their operative and inoperative positions by means of a pushknolb, which projected through a slot in the housing. In these devices, the writing units or implements were shifted [from the inoperative into the operative or writing position by placing a finger or thumb on the push-knob, and urging the knob downwardly, which in turn forced the writing implement into writing position. The knob was normally spring-loaded, so it engaged a catch to hold the writing implement in its writing position. The knobs sprang lback automatically into their inoperative position when the push-knob was disengaged from its catch or was pressed inwardly.

These known selective multiple unit writing instruments were objected to in that the unit or implement, while being used, often sprang back to its inoperative positionowing to accidental disengagement of the locking means. This occurred if the catch knob projecting from the housing was inadvertently depressed by a finger of the user during writing. Also, since normally the knobs or levers for operating the various writing units projected radially outwardly from the housing, the unit was uncomrfortable to hold, especially for long periods.

Various means have been proposed for overcoming these defects which have slotless outer jackets or housings, but which mechanisms for accomplishing the longitudinal movement of a selected writing implement were complex and dilficult to assemble or repair and expensive to make.

In accordance with the present invention, a Writing instrument is provided having a plurality of selectable writing units, which is easy and comfortable to hold, and simple to assemble and to use.

It is accordingly an object of the present invention to provide a simple, thin, multiple unit writing instrument,

which is highly efficient in operation and comfortable to use.

It is a further object of the present invention to pro- \vide a multiple unit ball point pen, having a precision selector mechanism for selecting the desired cartridge, which mechanism is not subject to excessive wear or malfunctioning.

Still another object of the present invention is to provide a ball point cartridge {for use with a rotational selector mechanism, which allows simple replacement, positive, reliable action, and insures proper positioning in the pen barrel.

Yet another object of the present invention is to provide an improved multiple unit selector mechanism, which either a short left hand or a short right hand rotational movement of the turn-cap of the instrument.

It is a further object of the present invention to provide a multiple uni-t ball point pen which allows easy and quick replacement Of the cartridges without disassembly of the pen.

It is still a further object of the present invention to provide a writing instrument which accomplishes all of the above and yet is simple and inexpensive to manufacture, positive-acting and pleasing in appearance.

Other and further objects and features of the present invention will become apparent to those skilled in the art from a consideration of the attached drawings, in which one embodiment of the invention is illustrated by way of example only, and wherein:

[FIGURE 1 is a front elevational view, partly broken away and in section, illustrating a writing instrument in accordance with the present invention, having two writing units, one of which is in writing position;

FIGURE 2 is a front elevational view similar to FIG- URE 1, partly broken away and in section, showing the other writing unit being withdrawn;

FIGURE 3 is an enlarged longitudinal sectional view of the selector mechanism, taken along line 33, illustrating one writing unit locked in Writing position;

FIGURE 4 is a cross-sectional view taken along line 44 of FIGURE 3;

[FIGURE 5 is a cross-sectional view taken along line 5 5 of FIGURE 3;

FIGURE 6 is an exploded view, slightly enlarged showing the writing units assembled in a sleeve with the retainer clip shown in position to be clipped in place;

FIGURE 7 is a front elevational view, partly broken away and in section illustrating a further embodiment;

FIGURE 8 is a fragmentary cross-sectional view taken along line 8-8 of FIGURE 9;

FIGURE 9 is a cross-sectional view taken along the line 99 of [FIGURE 7;

FIGURE 10 is a cross-sectional view taken along line 10*10 of FIGURE 7;

FIGURE 11 is a fragmentary cross-sectional view of the lower portion of the embodiment shown in FIGURE 7 illustrating removal of a cartridge;

FIGURE 12 is a fragmentary enlarged cross-sectional view taken along line 12-412 of FIGURE 13 illustrating a rfiurther embodiment;

FIGURE 13 is an enlarged broken away cross-sectional view showing a further embodiment of the feeding mechanism; and

FIGURE 14 is a cross sectional view taken along line 1414 of FIGURE 12.

Preferably, the individual writing units comprise a ball point pen type cartridge of generally conventional configuration, and of standard length having a ball point at one end with ink reservoir communicating therewith.

The present invention has particular applicability to utilizing two writing units of contrasting colors to permit the user easy, positive selection of the color of his choice.

Referring to FIGURES l-6, a multi-unit writing instrument generally indicated at 10 is illustratively shown with two writing units 12 and 14 reciprocally mounted within a cylindrical casing formed by a barrel or body portion 16 and a cap 18. Barrel 16 is generally tubular in shape and has a lower or forward reduced end portion 20 having an opening 22 at its end.

permits the selection of the desired writing implement by As is generally shown in FIGURES 1 and 2, securely mounted on the rearward end of barrel 16 opposite to the end having opening 22 therein is a drum or inner sleeve 24. Advantageously, sleeve 24 is press-fitted into barrel 16 and extends rearwardly from the upper end portion of barrel 16. The portion of sleeve 24 is slightly undercut to rotatably receive cap 18 as discussed below.

Sleeve 24 has a pair of longitudinal compartments or recesses 26 therein, extending downwardly from the upper edge of sleeve 24 a predetermined distance. The lower portion of sleeve 24 is tubular, enclosing a volume 27. Interconnecting each of compartments 26 and volume 27 is an opening 29, smaller in diameter than its corresponding compartment 26, for forming an inwardly projecting annular shoulder 28 in each compartment 26. As seen best in FIGURE each of compartments 26 has a rectangular corner section, indicated at 25, opposite to each other, which as discussed hereafter prevents the writing units 12 and 14 from being inserted improperly. Compartments 26, volume 27, and opening 29 have their respective longitudinal axes parallel. Writing units 12 and 14, which as shown are ball point pens, have smaller diameters than openings 29, so as to be slidably movable within said openings.

Mounted on the ends of writing units 12 and 14 opposite to the writing tip is a plug or head 30. Plug 30 has a reduced diameter portion 31 which is fixedly received within a corresponding end of the ink reservoirs of writing units 12 and 14. Tlug 30 has a diameter larger than the outer diameter of its mating ink reservoir, but small enough to be slidably movable within longitudinal compartments 26. Each of plugs 30 has a square corner extension 33 to mate with square corner of its corresponding compartment 26. Extending radially outwardly from each of plugs is a pin or arm 32. Advantageously, plug 30 has a longitudinal opening 35 passing therethrough to provide an air vent for the ink supply in the ink reservoir in the writing unit.

Mounted about the outer surface of writing units 12 and 14 respectively, adjacent plug 30, are compression springs 34, which serve to retract writing units 12 and '14. Each spring 34 has a diameter greater than the diameter of opening 29 within sleeve 24. The lower end of spring 34 abut corresponding shoulders 28, as best seen in FIGURES 2 and 3. In assembling the writing device, a spring 34 is slipped over the body of its respective writing unit from its writing end, until it abuts against the undersurface of plug 30 and the writing unit is slipped into its respective compartment 26, so that the lower end of the spring rests on the upper surface of shoulder 28 corresponding to its compartment 26. Springs 34 are normally expanded and biased to hold their respective writing units in the upper retracted position as seen best in FIGURE 1. Either of the writing units may be projected downwardly into extended or operative position as shown in FIGURE 2, by a movement of the selector mechanism in a manner as will be discussed hereinafter.

The upper end of sleeve 24, designated as 24a, is reduced in diameter, as best seen in FIGURES 2 and 6. Sleeve portion 24a has a pair of axially aligned, longitudinally extending slots 3-8, each communicating with a corresponding compartment 2 6. Slots 38 have a width slightly greater than the diameter of its corresponding pin 32 on plug 30. Writing units :12 and 14 with plugs 30 mounted thereon, when assembled within their corresponding longitudinal compartment 26, have their corresponding pin 32 projecting through slot 38 and outwardly beyond the outer surface of reduced portion 24a of sleeve 24, as best seen in FIGURE 4. As seen best in FIGURE 4 reduced portion 24a of sleeve 24 has diametrically opposed, two flattened longitudinal sections 37 and 39 respectively, and called flats. Flat 39 has a semi-spherical or a hemispherical knob 41 extending therefrom.

Mounted on the top of portion 24a of sleeve 24 is a retainer clip 60 having a pair of downwardly extending arms 62 and 64 as shown best in FIGURE 6. Arms 62 and 64 are of a width and spaced apart to frictionally engage flats 37 and 3!? of sleeve 24 respectively. Arm

64 is longer than arm 62 and has an opening 66 therein to mate with knob 41 as best seen in FIGURE 4. Knob 41 holds clip 61 securely in position, so as to prevent accidental displacement. Extending from opposite edges of clip 64 and at right angles to arms 62 and 64 are a further pair of downwardly extending arms or lugs 68 and 70. Arms 68 and 70 are spaced apart and are of a size to be received in compartment 26, as shown best in FIGURES 3 and 4. The bottom edge of arms 68 and 70 bear on the upper surfaces of plugs 341. With clip 66 mounted on sleeve 24 writing units 12 and 14 will not be accidentally displaced during assembly or refilling of the writing instrument.

Cap 18 is rotatably mounted on sleeve 24. The inner diameter of the lower portion of cap 18 is substantially the same as the outer diameter of sleeve 24, so that the inner surface of cap 18 is spaced from the outer surface of sleeve portion 24a, as best seen in FIGURES 2 and 5. The outer diameter of cap 18 is substantially the same as the outer diameter of barrel 16 and the lower edge of cap 18 abuts the upper edge of barrel 1-6 when in its operative position to form a uniform, smooth holding surface.

Disposed about a portion of the outer peripheral surface of sleeve 24 adjacent the reduced diameter portion 24a, is a circumferential depression or groove 40, which acts as a guide slot for mounting cap 18 positively on sleeve 24. Depression 40 is of a width corresponding to a detent or projection 42 projecting inwardly from the inner surface of cap 18. A portion of the outer surface of sleeve 24 above and adjacent depression 4! is undercut to allow detent 42 to be urged past and be sprung into depression 40, to positively hold cap 18 in place during rotation, as best seen in FIGURE 3. Cap 18 is thus locked onto sleeve 24 in abutting, mating position with respect to barrel 16 when detent 42 is in register with depression 40. Cap 18 is rotatable with respect to barrel 16 through a predetermined angular relation by reason of the arc length of depression 40.

Disposed within cap 18 is the actuator mechanism. Fitted within cap 18, generally concentric to the axis of sleeve 24 is a guide sleeve 44 having a cam surface 46 along its lower edge. Guide 44 is afiixed to cap '18 in any convenient manner, preferably by press fit or pins, or by action of clip, not shown, which has lugs 54 extending through the wall of cap 18 and guide 44. As shown, guide sleeve 44 is adjacent the inner wall of cap 18 and has a smaller thickness than the space between the inner wall of cap 18 and reduced portion 24a of sleeve 24. Cam surface 46 ascends obliquely from its lowermost point or writing position 47 uniformly on both sides of said point to a point most distant from barrel opening 22, indicated at 49 in FIGURE 3. At the lowermost point 47 of cam surface 46 is a notch or indent 48 of a diameter, which mates with pin 32, to prevent accidental displacement of the writing implement in a manner as disclosed hereinafter.

When cap 18 is asembled on sleeve 24 each of pins 32 of plugs 30 is urged against cam surface 46 by action of its spring 34. Rotation of cap 18 about sleeve 24 in either direction also rotates guide 44, causing pins 32 to slide upwardly or downwardly in slots 38 along cam surface 46. The circumference of depression 40 along the outer surface of sleeve 24 limits the rotational movement of cap 18, which in turn limits the rotational movement of cam surface 46 to provide speedy selection of the desired unit. When both writing units 12 and 14 are in their inoperative position, as viewed in FIGURE 2, their respective pins 32 are disposed along cam surface 46 intermediate of its lowermost point 47 and the uppermost point 49. As shown in FIGURES 1 and 2, rotation of cap 18 in the clockwise direction, feeds writing unit 12 nto operative or writing position against the pressure of its corresponding compression spring 34 and writing unit 14 is urged upwardly along cam surface 46 by reason of action of its respective spring 34. If cap 18 were rotated in a counterclockwise direction, as shown by the direction of arrow 50, writing unit 14 would be displaced into its operative position and writing unit 12 would be displaced further from opening 22 in barrel 16. A preferred angular range for movement of cap 18 found to give the desired flexibility is about 90 on each side of rest or inoperative position. Thus cap 18 need only be rotated 90 in either direction to be ready for operation.

When it isdesired, to remove or replace any one of the writing units, the user twists cap 18 in depression 40 until the Writing units 12 and 14 are in operative position and forces cap 18 over reduced section or surface 44. Clip 60 is snapped off of sleeve 24 and the user tips barrel 16 which frees writing units 12 and 14 from sleeve 24 and a new writing unit having a plug 30 fixedly positioned in the end of its reservoir is slid back into the corresponding opening and through the compression spring 34. By reason of square corner 33 on plugs 30 mounted on the writing units the units can only be inserted properly. Clip 60 is snapped back into position on sleeve 24 and the cap end is remounted on sleeve 24 in the manner as discussed previously and the writing device is ready to use.

A clip may be fixedly positioned in a conventional manner on cap 18. Also, a shown, the upper end of cap 18 has generally vertically aligned grooves 56 therein to aid in firmly gripping unit to provide an easy means of the user rotating cap 18.

A further embodiment of the present invention is shown in FIGURES 7-11, wherein a writing instrument 80 is shown. Instrument 80 is generally similar in construction as writing instrument 10' described above and has two writing units 82 and 84 reciprocally mounted within a body portion 86 and a cap 88. Body portion 86 has an opening 90 in its lower end through which writing units 82 and 84 project alternatively, when in operative position.

Securely mounted on the rearward end of barrel 86 is a sleeve 92, which extends rearwardly from barrel 86. Sleeve 92 has a pair of longitudinally extending, generally parallel compartments 94 therein, extending downwardly from the upper edge of sleeve 92 a predetermined distance. The lower portion of sleeve 92 is tubular and hollow and open at its lower end. Compartments 94 intersect with the hollow interior of the lower portion of sleeve 92. At this intersection is an interiorly projecting annular shoulder 96. The upper portion of sleeve 92 has a reduced outer diameter, designated as 98a, which is generally coextensive with the length of compartments 94. Sleeve portion 92a has a pair of longitudinally extending slots 98, which as shown in FIGURES 9 and 10 are axially aligned. Slots 98 communicate with a corresponding compartment 94 and are of a length substantially equal to reduced portion 92a.

Slidably mounted in each of compartments 94 is a generally tubular member or tube 100. As best seen in FIGURE 11, the outer diameter of tube 100 is larger than opening 90 to prevent displacement during use. Mounted on the rearward ends of tubes 100 are plugs 102. Plugs 102 have a reduced diameter lower portion 104 which is fixedly received within the rearward end of its corresponding tube 100. Advantageously, plug 102 has a diameter substantially equal to the outer diameter of tube 100, so as to be slidably movable within its corresponding compartment 94. Extending radially outwardly from each of plugs 102 is a pin or arm 10'6 having a width to be slidably received within its corresponding slot 98 and extending outwardly a distance greater than the outer surface of sleeve portion 92a Extending rearwardly from each of plugs 102 is an extension or shoulder 10 8. Extension 108 has a downwardly flared outwardly extending lip 110.

As best seen in FIGURE 8, mounted about each extension 108 is a spring 112. The bottom end of spring 112 has an inner diameter which is generally equal to the length of extension 108- and is forced over lip 110, so as to be held firmly in position on its corresponding plug 102. Springs 112 extend up through corresponding compartments 94. The upper end of each spring 112 is larger in diameter than the diameter of its corresponding compartment 94 and rests on the upper end of sleeve 92. Springs 112 retract tubes in a manner described below.

Slidably inserted in each of tubes 100 are writing units 82 and 84. Advantageously, writing units 82 and 84 are crimped slightly to make them slightly out of round so as to frictionally engage tube 100 and prevent accidental removal. Writing units 82 and 84 are forced into tubes 100 so that their upper ends abut the corresponding lower end of lower portions 104 of plug 102 as seen best in FIGURE 8. Writing units 82 and 84 are snugly held by its corresponding tube 100 and operate as a unit.

Cap 88 is rotatably mounted on sleeve 92. Cap 88 is spaced from the outer surface of reduced portion 92a of sleeve 92 similar as described above in the first embodiment.

Rotatably mounted on and generally concentric to reduced sleeve portion 92a is a guide sleeve 116 having a cam surface 118 along its lower edge. Guide sleeve has an inwardly directed hp 120, which rot-atably mates with an annular groove 122, circumferentially disposed about the outer surface of reduced sleeve portion 92a. Groove 122 is preferably bounded on its upper edge by a lip 124 formed on sleeve portion 9211 by an outwardly flared section, as best seen in FIGURES 7 and 8. Lip 124 aids in assembly of guide sleeve 116 on sleeve portion 92a. Guide sleeve 116 is preferably press-fitted within cap 88, so as to turn with cap 88. As shown, guide sleeve 116 has a generally elliptical cross section so that lip engages a portion of groove 122. Guide sleeve 116 has a slightly smaller thickness than the space between the inner surface of cap 88 and the outer surface of reduced sleeve portion 92a.

Cam surface 118 has a pair of notches 126 and 128 on opposite sides of stop finger 130. Cam surface 118 ascends obliquely uniformly from each of notches 126 and 128. Notches 126 and 128 inate with pins 106 of corresponding writing units 82 and 84.

Writing instrument 80 is operated in a manner generally similar to the first described embodiment. When cap 88 is rotated in either clockwise or counter-clockwise direction, a pin 106 is received in a corresponding notch 126 or 128. As seen in FIGURE 7, cap 88 was rotated in the clockwise direction (arrow 132) to engage pin 106 in notch 126. Cap 88 cannot be rotated further in this direction by reason of finger 130 engaging pin 106. Pin 106 is movable longitudinally only and resists further rotational movement. To position the remaining writing unit in operative position, cap 88 is rotated in the reverse direction from arrow 132 until pin 106 is received in its notch 128.

To remove or replace writing unit 82, as best seen in FIGURE 11, writing unit 82 is positioned in operative position and forcibly removed from tube 100 by the fingernails of the user. A new cartridge is inserted into tube 100. Preferably writing unit 82 engages. the bottom surface of plug 102, as shown in FIGURE 8 to be correctly positioned. P-ins 106 remain in contact with cam surface 118 by retractile springs 112.

In assembly, guide sleeve 116 is mounted on sleeve portion 92a which because of longitudinally extending slots 98 is flexible. Lip 120 is sprung past llip 124 into groove 122.

A further embodiment of .the present invention is shown in FIGURES 12-14. This embodiment is generally similar to the embodiment shown in FIGURES 7 to 11 and like numerals indicate like parts.

Rotatably mounted on reduced sleeve portion 92a is a guide sleeve having a cam surface 142 along its lower edge. Guide sleeve 140 has an inwardly directed lip 144 which mates with a groove 146 extending circum ferentially about the outer surface of reduced portion 92a, adjacent its upper edge. Groove 146 has a portion 146a having a greater depth to form two abutments 147. Lip 144 has a portion 144a extending radially inwardly to mate with groove portion 146a. Lip 144a operatively cooperates with abutments 147 to selectably restrict rotation of guide sleeve 140. Preferably, lip 144a extends circumferentially about an angle of 90 and groove portion 146a extends circumferentially about an angle of 270. As best' seen in FIGURE 14, abutments 147 are positioned with respect to corresponding pins 106, so that when lip portion 144a engages an abutment 147, the cam is operatively positioned with respect to the corresponding pin 106. Preferably, cam surface 142 has a notch 148 in its lowermost portion, which engages a selected pin 106. A vertical plane passing through the center line of notch 148 bisects lip portion 144a.

Guide sleeve 140 is fixedly received within cap 88 in any suitable manner, so that rotating cap 88 on sleeve 92 rotates guide sleeve 140. Rotating cap 88 in clockwise direction causes one end of sleeve lip portion 14451 to engage one abutment 147, when notch 148 engages one of the pins 106. Similarly, rotating cap 88 about 180 in the opposite direction engages the opposite end of lip portion 144a to engage the other abutment 147 when notch 148 engages the other pin 106 to move the other writing unit in operative position.

Writing units 82 and 84 can remain in inoperative position when notch 148 is positioned between pins 106.

It is seen that an extremely simple multiple writing instrument is provided with a minimum number of parts and yet retaining all of the advantages afforded by multiple type writing instruments. The outer surface of body of the writing unit is smooth and uniform for more comfortable gripping and holding during use as well as making a pleasing esthetic impression. The selector mechanism is positive, quick-acting and smoothly operating with no jolt-ing which causes undue wear. Only a small angular movement of cap 18 makes the instrument 10 ready to operate. This lack of 360 continuous rotation of the cap avoids any error or fumbling about the choice of which writing unit to use. For example, if writing unit 12 were blue and unit 14 were red, the user will know that blue ink will always be available for use if cap 18 were rotated clockwise, from the inoperative position and red would be available if cap 18 were rotated counterclockwise. Also, if desired, two similar colored cartridges may be used so that one is available as a spare.

Although particular structures and embodiments have been described by way of illustration, it should be understood that the invention should not be limited to the particular embodiments of the invention shown by way of illustration, but rather to the scope of the invention covered by the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A multiple unit writing instrument comprising an elongated generally tubular body having an opening at one end, a pair of Writing units having writing means at one end disposed within said tubular body with said writing means facing said body opening, said writing units adapted for reciprocal longitudinal motion with said body, a cam surface rotatably disposed within said body and having a lowermost surface facing said body opening, follower means coupled to each of said writing units, each of said follower means abutting said cam surface on an opposite side of and about a 90 are from said lowermost cam surface, means for rotating said cam surface, and stop means cooperating with said rotating means for limiting rotation of said lowermost cam surface about 90 toward each of said follower means for urging said corresponding follower means and its corresponding writting unit downwardly towards said body opening and into operative writing position.

2. A multiple unit writing instrument comprising an elongated generally tubular body having an opening at one end, a pair of writing units having writing means at one end disposed within said tubular body with said writing means facing said body opening, said writing units adapted for reciprocal longitudinal motion within said body, a cam surface rotatably disposed within said body, said cam surface ascending from a lowermost point uni- :formly on 'both sides of said point away from said body opening, means for rotating said cam surface about its longitudinal axis, follower means interconnected with each of said writing units and abutting said cam surface on opposite sides of and spaced about from said lowermost point of said cam surface, and stop means cooperating with said cam surface to limit rotation of said lowermost point of said cam surface about 90 in each direction, whereby said cam surface being rotated about 90 towards one follower means is stopped by said stop means when said one follower means abuts said cam surface to position said one writing unit in operative position.

3. A multiple unit writing instrument comprising an elongated generally tubular body having an opening at one end, a pair of longitudinal guide means disposed within said body in spaced parallel relation, a pair of writing units halving writing means at one end generally longitudinally disposed within said tubular body with said writing means facing said body opening, said writing units adapted for longitudinal reciprocal motion within said body, a pair of pins each cooperating with one of said guide means and adapted for longitudinal movement, means interconnecting a pin with a corresponding writing unit, a cam surface disposed within said body and intersecting the paths of longitudinal movement of said pins, said cam surface ascending from a lowermost point uniformly on both sides of said point away from said body opening, means for rotating said cam surface in clockwise and counterclockwise directions so that said lowermost point alternatively engages said pins, stop means operatively cooperating with said cam surface for limiting further rotation of said cam surface in one direction when said lowermost point engages one of said pins, and means continuously urging said pins against said cam surface, whereby rotating said cam surface in either direction until engaging said stop means urges one of said pins and its corresponding writing unit downlwardly towards said body opening and said pin engages said lowermost point of said cam surface for positioning its corresponding writing unit in operative position.

4. A multiple unit writing instrument as described in claim 3, wherein said lowermost point of said cam has a notch to receive said pin.

5. A selectable multiple unit writing instrument comprising an elongated gene-rally tubular body portion having two ends with an opening at one end, a sleeve fixedly mounted on the other end of said body portion and extendingrearwardly therefrom, said sleev having a pair of opening therein parallel to the longitudinal axis of said body portion and each having a longitudinal slot communicating therewith, a pair of writing units each slidably disposed in a corresponding sleeve opening and having one end extending into said body portion and facing said body portion opening, a pin laterally projecting from each of said writing units and extending through the slot in said corresponding sleeve opening, retractile means cooperating with each of said writing units, a cap rotatably mounted on said sleeve for movement in clockwise and counterclockwise direction, a cam surface coaxially mounted within said cap and ascending from a lowermost point uniformly on both sides of said lowermost point towards the rear end of said cap, said cam surface bearing against said pins, said lowermost point corresponding to the writing position of the respective writing unit wbose pin bears against said lowermost point, and a pair of stop means on said sleeve cooperating with said cap and positioned with respect to said pins for stopping rotation of said cap in one direction when said cam lower-most point engages a corresponding pin, whereby rotating said cap causes said cam surface to urge one of said pins and its corresponding writing unit downwardly towards said body opening until said one pin abuts said lowermost point and its corresponding writing unit is in operative position and the remaining writing units are maintained in inoperative position within said body portion.

'6. A multiple unit writing instrument as described in claim wherein said lowermost point of said cam has a notch to receive said pin.

7. A selectable multiple unit writing instrument com prising an elongated body portion having two ends with an opening at one end, a sleeve fixedly mounted on the other end of said body portion and extending rearwardly therefrom, said sleeve having a pair of openings therein parallel to the longitudinal axis of said body port-ion and each having a longitudinal slot communicating therewith, said sleeve having a reduced diameter portion containing said slots, a writing unit slidably mounted in a corresponding sleeve opening and extending into said body portion with one end facing said body portion opening, said unit having a radially enlarged surface at the other end, a pin laterally projecting from said enlarged surface and extending through the slot in said corresponding sleeve opening, retractile means for each of said writing units, a cap rotatably mounted on said sleeve for movement in clockwise and counterclockwise directions, said cap being spaced from the outer surface of said reduced portion of said sleeve, a cam surface mounted within said cap and disposed within the space formed by said cap and said reduced portion of said sleeve, said cam surface ascending from a pin engaging point uniformly on both sides of said point towards the rear end of said cap, means for simultaneously rotating said cam surface and said cap, said cam surface bearing against said pins, said pin engaging point corresponding to the writing position of the respective writing unit, which pin bears against said point, and stop means operatively cooperating with said cam surface for limiting further rotation of said cam surface in one direction when said pin engaging point bears against a pin, whereby rotating said cap causes said cam surface to urge one pin of a corresponding writing unit downwardly towards the body opening until said one pin abuts said lowermost point and its corresponding writing unit is in operative position and the other writing unit is maintained inoperative position within said body portion.

8. A writing unit comprising a first elongated tube having a generally circular cross section, a plug mounted on one end of said tube and having a pin projecting outwardly beyond the outer surface of said tube substantially transverse to the longitudinal axis of said tube, a second elongated tube removably receivable within said first tube and having a portion with a noncircular cross section slightly greater than the diameter of said first tube, so as to be frictionally engageable therewith, a spherical element rotatably mounted at one end of said second tube and projecting partially therefrom, a supply of writing fluid contained in said second tube, and means feeding said writing fluid to said spherical element, said second tube being of a length so that its other end abuts the plug end of said first tube when said one end of said second tube extends beyond the other end of said first tube.

9. A writing unit as described in claim 8, further comprising an elongated tubular casing having an open ing in one end within which said first and second tubes are reciprocally mounted for longitudinal movement, said casing opening being smaller than the outer diameter of said first tube and larger than the outer diameter of said second tube, so that only said sec-0nd tube can project through said opening and can be removed from said casin and actuator means for selectably longitudinally moving said first tube within said casing between a projected writing position of said one end of said second tube to a retracted position.

.10. A multiple unit writing instrument comprising an elongated generally tubular body having an opening at one end, a pair of writing units having writing means at one end disposed within said tubular body with said writing means facing said body opening, said writing units adapted for reciprocal longitudinal motion within said body, a cam surface rotatably disposed within said body, said cam surface ascending from a lowermost point uniformly on both sides of said point away from said body opening, means for rotating said cam surface about its longitudinal axis in clockwise and counterclockwise directions, follower means coupled to each of said writing units and abutting said cam surface on opposite sides of and spaced a predetermined arc from said lowermost point of said cam surface, and stop means cooperating with said cam surface to limit rotation of said cam surface about said predetermined arc in a clockwise and counterclockwise direction, whereby said cam surface being rotated through said predetermined arc towards one follower means is stopped by said stop means when said one follower means abuts said'cam surface to position said one writing unit in operative position.

11. A writing instrument as described in claim 10, wherein said stop means comprise a sleeve within which said writing units reciprocate, said sleeve having a pair of shoulders spaced a predetermined angle from said follower means, said cam surface being rotatably mounted on said sleeve and having opposite edges adapted to engage corresponding ones of said shoulders to stop rotation of said cam.

12. A writing instrument as described in claim 10, wherein said stop means comprises a finger adjacent said lowermost point of said cam surface, said finger adapted to engage the follower means toward which said cam surface is rotated to stop rotation of said cam surface.

References Cited by the Examiner UNITED STATES PATENTS 12,494,967 11/1950 Sams r -18 2, 826,173 3/ 8 Gross Weiler et al. 120-14.5

FOREIGN PATENTS 59,263 1/ 1954 France. 873,636 3/ 1942 France. 965,615 2/ 1950 France. 985,040 3/1951 France. 1,270,645 7/ 1961 France. 444,447 1/1949 Italy. 446,650 3/ 1949 Italy. 518,042 3/ 1955 Italy.

LAWRENCE CHARLES, Primary Examiner. 

1. A MULTIPLE UNIT WRITING INSTRUMENT COMPRISING AN ELONGATED GENERALLY TUBULAR BODY HAVING AN OPENING AT ONE END, A PAIR OF WRITING UNITS HAVING WRITING MEANS AT ONE END DISPOSED WITHIN SAID TUBULAR BODY WITH SAID WRITING MEANS FACING SAID BODY OPENING, SAID WRITING UNITS ADAPTED TO RECIPROCAL LONGITUDINAL MOTION WITH SAID BODY, A CAM SURFACE ROTATABLY DISPOSED WITHIN SAID BODY AND HAVING A LOWERMOST SURFACE FACING SAID BODY OPENING, FOLLOWER MEANS COUPLED TO EACH OF SAID WRITING UNITS, EACH OF SAID FOLLOWER MEANS ABUTTING SAID CAM SURFACE ON AN OPPOSITE SIDE OF AN ABOUT A 90* ARC FROM SAID LOWERMOST CAM SURFACE, MEANS FOR ROTATING SAID CAM SURFACE, AND STOP MEANS COOPERATING WITH SAID ROTATING MEANS FOR LIMITING ROTATION OF SAID LOWERMOST CAM SURFACE ABOUT 90* TOWARD EACH OF SAID FOLLOWER MEANS FOR URGING SAID CORRESPONDING FOLLOWER MEANS AND ITS CORRESPONDING WRITTING UNIT DOWNWARDLY TOWARDS SAID BODY OPENING AND INTO OPERATIVE WRITING POSITION. 